Cover Crops in Corn-Soybean Rotations in the Upper Midwest.

Corn-soybean rotations predominate in much of the Upper Midwest.  As a result, cover crops are restricted to a realtively short growth window and winter cereals are the most widely used cover crops.  In spite of this, cover crops can have substantial impacts on reducing erosion, decreasing nitrate leaching losses, and improving soil health.  Winter cereal cover crops can have some negative impacts on corn yield and neutral or positive impacts on soybean yields.